The QTc (485 to 505 milliseconds) shortened during normalization of calcium levels, and syncope has not reoccurred. An adolescent presented with exercise-associated syncope and electrocardiographic corrected QT interval (QTc) prolongation. Pseudohypoparathyroidism-induced hypocalcemia was diagnosed.

From a screening perspective, a QTc value ≥470 ms for a 2–4-week-old infant screening programme or a QTc ≥500 ms in adolescents/adults may represent far more optimal “penalty box” screening values with an estimated positive predictive value >50%.

Consider extended, mobile cardiac outpatient telemetry (MCOT) monitoring for selected COVID-19 patients that have other high-risk features for cardiac arrhythmias including family history of sudden cardiac death, elevated troponin, or elevated NT-pro BNP.

2021年6月21日 · We aimed to describe the prevalence of QTc prolongation among patients with cancer and how CTCAE adverse events vary using different QTc formulae. We also sought to describe how frequently QTc prolongation influenced clinical management at our institution and whether the use of a specific QTc formula may have changed clinical decision-making.

The prolonged QT (QTc = 485 ms) was incidentally found on electrocardiogram (ECG) obtained due to hyperkalemia. Worsening QT prolongation (QTc = 505 ms) and T wave inversion in the lateral leads were also observed on ECG after the next hemodialysis session two days later raising concerns for ischemia (Figure 1A ).

2009年7月1日 · Corrected QT interval was measured for all normal beats from 32 recordings of baseline rhythm and compared to normal rhythm before a paired spontaneous cardiac arrhythmia. Before arrhythmia, the QTc (505 ± 73 ms) was not significantly longer than the baseline rhythm (497 ± 73 ms) ( P = .23).

This review discusses the components of accurate QTc measurement and diagnosis, re-examines what is known about factors affecting QT interval measurement, and clarifies current recommendations regarding diagnosis of so-called “borderline” QT interval prolongation.

2009年7月1日 · This retrospective study describes the changes in the QTc interval and heart rate before fast VT/VF and VT in patients with a WCD. After investigating various groups including arrhythmia type and onset, a significant change in QTc was not found, when comparing baseline to onset of a ventricular arrhythmia.

2000年3月1日 · An adolescent presented with exercise-associated syncope and electrocardiographic corrected QT interval (QTc) prolongation. Pseudohypoparathyroidism-induced hypocalcemia was diagnosed. The QTc (485 to 505 milliseconds) shortened during normalization of calcium levels, and syncope has not reoccurred.

2024年7月12日 · 如心電圖展示 QTc > 500 msec, 這是很不正常, 網上電郵診症, 盲點、危機四伏, 為可不找心臟專科醫生呢？ 如資源有限, 是明白的, 可以排政府, 有經驗的護士會分流處理, https://sads.org/drugs-to-avoid/ 謝謝。